content: package com.google.protobuf;
  
  import com.google.protobuf.Utf8.Processor;
  import com.google.protobuf.Utf8.SafeProcessor;
  import com.google.protobuf.Utf8.UnsafeProcessor;
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.logging.Logger;
  import junit.framework.TestCase;
  
  public class DecodeUtf8Test extends TestCase {
    private static Logger logger = Logger.getLogger(DecodeUtf8Test.class.getName());
  
    private static final Processor SAFE_PROCESSOR = new SafeProcessor();
    private static final Processor UNSAFE_PROCESSOR = new UnsafeProcessor();
  
    public void testRoundTripAllValidChars() throws Exception {
      for (int i = Character.MIN_CODE_POINT; i < Character.MAX_CODE_POINT; i++) {
        if (i < Character.MIN_SURROGATE || i > Character.MAX_SURROGATE) {
          String str = new String(Character.toChars(i));
          assertRoundTrips(str);
        }
      }
    }
  
    // Test all 1, 2, 3 invalid byte combinations. Valid ones would have been covered above.
  
    public void testOneByte() throws Exception {
      int valid = 0;
      for (int i = Byte.MIN_VALUE; i <= Byte.MAX_VALUE; i++) {
        ByteString bs = ByteString.copyFrom(new byte[] { (byte) i });
        if (!bs.isValidUtf8()) {
          assertInvalid(bs.toByteArray());
        } else {
          valid++;
        }
      }
      assertEquals(IsValidUtf8TestUtil.EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, valid);
    }
  
    public void testTwoBytes() throws Exception {
      int valid = 0;
      for (int i = Byte.MIN_VALUE; i <= Byte.MAX_VALUE; i++) {
        for (int j = Byte.MIN_VALUE; j <= Byte.MAX_VALUE; j++) {
          ByteString bs = ByteString.copyFrom(new byte[]{(byte) i, (byte) j});
          if (!bs.isValidUtf8()) {
            assertInvalid(bs.toByteArray());
          } else {
            valid++;
          }
        }
      }
      assertEquals(IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT, valid);
    }
  
    public void testThreeBytes() throws Exception {
      // Travis' OOM killer doesn't like this test
      if (System.getenv("TRAVIS") == null) {
        int count = 0;
        int valid = 0;
        for (int i = Byte.MIN_VALUE; i <= Byte.MAX_VALUE; i++) {
          for (int j = Byte.MIN_VALUE; j <= Byte.MAX_VALUE; j++) {
            for (int k = Byte.MIN_VALUE; k <= Byte.MAX_VALUE; k++) {
              byte[] bytes = new byte[]{(byte) i, (byte) j, (byte) k};
              ByteString bs = ByteString.copyFrom(bytes);
              if (!bs.isValidUtf8()) {
                assertInvalid(bytes);
              } else {
                valid++;
              }
              count++;
              if (count % 1000000L == 0) {
                logger.info("Processed " + (count / 1000000L) + " million characters");
              }
            }
          }
        }
        assertEquals(IsValidUtf8TestUtil.EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT, valid);
      }
    }
  
    /**
     * Tests that round tripping of a sample of four byte permutations work.
     */
    public void testInvalid_4BytesSamples() throws Exception {
      // Bad trailing bytes
      assertInvalid(0xF0, 0xA4, 0xAD, 0x7F);
      assertInvalid(0xF0, 0xA4, 0xAD, 0xC0);
  
      // Special cases for byte2
      assertInvalid(0xF0, 0x8F, 0xAD, 0xA2);
      assertInvalid(0xF4, 0x90, 0xAD, 0xA2);
    }
  
    public void testRealStrings() throws Exception {
      // English
      assertRoundTrips("The quick brown fox jumps over the lazy dog");
      // German
      assertRoundTrips("Quizdeltagerne spiste jordb\u00e6r med fl\u00f8de, mens cirkusklovnen");
      // Japanese
      assertRoundTrips(
          "\u3044\u308d\u306f\u306b\u307b\u3078\u3068\u3061\u308a\u306c\u308b\u3092");
      // Hebrew
      assertRoundTrips(
          "\u05d3\u05d2 \u05e1\u05e7\u05e8\u05df \u05e9\u05d8 \u05d1\u05d9\u05dd "
              + "\u05de\u05d0\u05d5\u05db\u05d6\u05d1 \u05d5\u05dc\u05e4\u05ea\u05e2"
              + " \u05de\u05e6\u05d0 \u05dc\u05d5 \u05d7\u05d1\u05e8\u05d4 "
              + "\u05d0\u05d9\u05da \u05d4\u05e7\u05dc\u05d9\u05d8\u05d4");
      // Thai
      assertRoundTrips(
          " \u0e08\u0e07\u0e1d\u0e48\u0e32\u0e1f\u0e31\u0e19\u0e1e\u0e31\u0e12"
              + "\u0e19\u0e32\u0e27\u0e34\u0e0a\u0e32\u0e01\u0e32\u0e23");
      // Chinese
      assertRoundTrips(
          "\u8fd4\u56de\u94fe\u4e2d\u7684\u4e0b\u4e00\u4e2a\u4ee3\u7406\u9879\u9009\u62e9\u5668");
      // Chinese with 4-byte chars
      assertRoundTrips("\uD841\uDF0E\uD841\uDF31\uD841\uDF79\uD843\uDC53\uD843\uDC78"
          + "\uD843\uDC96\uD843\uDCCF\uD843\uDCD5\uD843\uDD15\uD843\uDD7C\uD843\uDD7F"
          + "\uD843\uDE0E\uD843\uDE0F\uD843\uDE77\uD843\uDE9D\uD843\uDEA2");
      // Mixed
      assertRoundTrips(
          "The quick brown \u3044\u308d\u306f\u306b\u307b\u3078\u8fd4\u56de\u94fe"
              + "\u4e2d\u7684\u4e0b\u4e00");
    }
  
    public void testOverlong() throws Exception {
      assertInvalid(0xc0, 0xaf);
      assertInvalid(0xe0, 0x80, 0xaf);
      assertInvalid(0xf0, 0x80, 0x80, 0xaf);
  
      // Max overlong
      assertInvalid(0xc1, 0xbf);
      assertInvalid(0xe0, 0x9f, 0xbf);
      assertInvalid(0xf0 ,0x8f, 0xbf, 0xbf);
  
      // null overlong
      assertInvalid(0xc0, 0x80);
      assertInvalid(0xe0, 0x80, 0x80);
      assertInvalid(0xf0, 0x80, 0x80, 0x80);
    }
  
    public void testIllegalCodepoints() throws Exception {
      // Single surrogate
      assertInvalid(0xed, 0xa0, 0x80);
      assertInvalid(0xed, 0xad, 0xbf);
      assertInvalid(0xed, 0xae, 0x80);
      assertInvalid(0xed, 0xaf, 0xbf);
      assertInvalid(0xed, 0xb0, 0x80);
      assertInvalid(0xed, 0xbe, 0x80);
      assertInvalid(0xed, 0xbf, 0xbf);
  
      // Paired surrogates
      assertInvalid(0xed, 0xa0, 0x80, 0xed, 0xb0, 0x80);
      assertInvalid(0xed, 0xa0, 0x80, 0xed, 0xbf, 0xbf);
      assertInvalid(0xed, 0xad, 0xbf, 0xed, 0xb0, 0x80);
      assertInvalid(0xed, 0xad, 0xbf, 0xed, 0xbf, 0xbf);
      assertInvalid(0xed, 0xae, 0x80, 0xed, 0xb0, 0x80);
      assertInvalid(0xed, 0xae, 0x80, 0xed, 0xbf, 0xbf);
      assertInvalid(0xed, 0xaf, 0xbf, 0xed, 0xb0, 0x80);
      assertInvalid(0xed, 0xaf, 0xbf, 0xed, 0xbf, 0xbf);
    }
  
    public void testBufferSlice() throws Exception {
      String str = "The quick brown fox jumps over the lazy dog";
      assertRoundTrips(str, 10, 4);
      assertRoundTrips(str, str.length(), 0);
    }
  
    public void testInvalidBufferSlice() throws Exception {
      byte[] bytes  = "The quick brown fox jumps over the lazy dog".getBytes(Internal.UTF_8);
      assertInvalidSlice(bytes, bytes.length - 3, 4);
      assertInvalidSlice(bytes, bytes.length, 1);
      assertInvalidSlice(bytes, bytes.length + 1, 0);
      assertInvalidSlice(bytes, 0, bytes.length + 1);
    }
  
    private void assertInvalid(int... bytesAsInt) throws Exception {
      byte[] bytes = new byte[bytesAsInt.length];
      for (int i = 0; i < bytesAsInt.length; i++) {
        bytes[i] = (byte) bytesAsInt[i];
      }
      assertInvalid(bytes);
    }
  
    private void assertInvalid(byte[] bytes) throws Exception {
      try {
        UNSAFE_PROCESSOR.decodeUtf8(bytes, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(bytes, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
  
      ByteBuffer direct = ByteBuffer.allocateDirect(bytes.length);
      direct.put(bytes);
      direct.flip();
      try {
        UNSAFE_PROCESSOR.decodeUtf8(direct, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(direct, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
  
      ByteBuffer heap = ByteBuffer.allocate(bytes.length);
      heap.put(bytes);
      heap.flip();
      try {
        UNSAFE_PROCESSOR.decodeUtf8(heap, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(heap, 0, bytes.length);
        fail();
      } catch (InvalidProtocolBufferException e) {
        // Expected.
      }
    }
  
    private void assertInvalidSlice(byte[] bytes, int index, int size) throws Exception {
      try {
        UNSAFE_PROCESSOR.decodeUtf8(bytes, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(bytes, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
  
      ByteBuffer direct = ByteBuffer.allocateDirect(bytes.length);
      direct.put(bytes);
      direct.flip();
      try {
        UNSAFE_PROCESSOR.decodeUtf8(direct, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(direct, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
  
      ByteBuffer heap = ByteBuffer.allocate(bytes.length);
      heap.put(bytes);
      heap.flip();
      try {
        UNSAFE_PROCESSOR.decodeUtf8(heap, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
      try {
        SAFE_PROCESSOR.decodeUtf8(heap, index, size);
        fail();
      } catch (ArrayIndexOutOfBoundsException e) {
        // Expected.
      }
    }
  
    private void assertRoundTrips(String str) throws Exception {
      assertRoundTrips(str, 0, -1);
    }
  
    private void assertRoundTrips(String str, int index, int size) throws Exception {
      byte[] bytes = str.getBytes(Internal.UTF_8);
      if (size == -1) {
        size = bytes.length;
      }
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          UNSAFE_PROCESSOR.decodeUtf8(bytes, index, size));
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          SAFE_PROCESSOR.decodeUtf8(bytes, index, size));
  
      ByteBuffer direct = ByteBuffer.allocateDirect(bytes.length);
      direct.put(bytes);
      direct.flip();
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          UNSAFE_PROCESSOR.decodeUtf8(direct, index, size));
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          SAFE_PROCESSOR.decodeUtf8(direct, index, size));
  
      ByteBuffer heap = ByteBuffer.allocate(bytes.length);
      heap.put(bytes);
      heap.flip();
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          UNSAFE_PROCESSOR.decodeUtf8(heap, index, size));
      assertDecode(new String(bytes, index, size, Internal.UTF_8),
          SAFE_PROCESSOR.decodeUtf8(heap, index, size));
    }
  
    private void assertDecode(String expected, String actual) {
      if (!expected.equals(actual)) {
        fail("Failure: Expected (" + codepoints(expected) + ") Actual (" + codepoints(actual) + ")");
      }
    }
  
    private List<String> codepoints(String str) {
      List<String> codepoints = new ArrayList<String>();
      for (int i = 0; i < str.length(); i++) {
        codepoints.add(Long.toHexString(str.charAt(i)));
      }
      return codepoints;
    }
  
  }
  